


A Rate of Conversion

by autoschediastic



Category: Supernatural
Genre: Bodyswap, M/M, Sibling Incest
Language: English
Status: Completed
Published: 2010-01-28
Updated: 2010-01-28
Packaged: 2017-10-06 18:51:50
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,546
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/56734
Author URL: https://archiveofourown.org/users/autoschediastic/pseuds/autoschediastic
Summary: <blockquote class="userstuff">
              <p>"What the hell are you doing sleeping naked in the same room as me!"</p>
            </blockquote>





	A Rate of Conversion

When Sam first wakes up, he thinks maybe he's coming down with the flu. The back of his throat is scratchy and his skin feels hot, tight like he's dehydrated. He knuckles sleep from his eye, fumbling for the bedside lamp. It takes him a minute to realise he's groping at empty. He flings his other arm out the opposite side of the bed.

The light blazes to life. The alarm radio on the nightstand says it's half past five in the morning. Sam blinks away the dots in his vision and catches sight of himself in the kitschy mirror above the dresser. His skin is pasty except for the darker skin bagging under his eyes, which are exactly as red and sore as they feel.

He's fucking _hungover_.

"Sammy," Dean groans, heaving himself onto his back like a sloth. He blows a chunk of sleep-messy hair from his face. "Would ya- Huh."

"Who the _hell_ did you piss off this time?" Sam demands, reluctantly impressed with the commanding boom of his--Dean's--voice. He's not sure Dean's ever managed to sound quite so imposing.

"What the fuck d'you mean, _me_?" Dean tosses back. Tumbling out of bed, he gropes awkwardly along the edge before he figures out Sam's centre of balance.

Which, alright, Sam supposes that's fair. He might've gotten them in a tight spot once or twice. But he's not going to admit that _now_, not when he's got Dean's wide eyes staring back at him in the mirror.

Dean's fumbled his way to their duffels and is rooting around with purpose. Triumphantly, he emerges with the ruler they use to forge basic IDs held high.

"This is your brilliant response?" Sam asks.

"I pride myself on never missing a golden opportunity."

"Your ego is incredible." Sam flings back the covers and ends up whacking his hand off the bedframe. He's halfway across the room, fully intent on snatching the ruler away and beating Dean senseless with it before he realises something is wrong.

Really, really wrong. More wrong than waking up wearing his brother's skin.

Waking up wearing _only_ his brother's skin, for example.

"Wow," Dean mouths. He tilts his head, lets his eyes rove slowly downward, lingering way too long on the morning wood his body's awkwardly sporting (because like hell Sam's got anything to do with _that_). "No wonder everybody wants a piece of me."

"What the hell are you doing sleeping naked in the same room as me!" Distantly, Sam notes that Dean is perfectly capable of shrieking like a seven year old girl. "Oh my god," he says. "Oh my god." He stumbles backwards, calves hitting the bed before he collapses onto it, head bowed into his hands. "You stink like spunk."

"Don't be stupid," Dean snorts. "It'd be dry by now, can't smell it."

Sam's eyes snap open, and he realises with utter clarity how bad an idea looking down is right now. Quickly, he jerks his head up and fixes Dean with what he hopes is the most withering glare Dean's stupid face is capable of producing.

"You just sit there and enjoy the feeling of an actual dick between your legs." Dean hooks his thumbs in the low-slung waistband of Sam's favourite pyjama pants, looking for all the world like he actually means to do it.

"I'm not kidding, Dean. You are not measuring my dick with that ruler."

"Got another one you want me to use?"

"Dean!"

Dean points the ruler accusingly at Sam's--Dean's, Jesus _Christ_\--crotch. "I see you ain't in a hurry to cover up the view."

"You're a dick." Sam jerks the blankets down to fling them over his lap. "A giant walking, talking, dick."

"Hey, don't be shy on my account." The malicious gleam in Dean's eyes--and Sam hopes to hell he never, ever looks like that, because he wouldn't be one bit surprised to see mothers grab up their children and scurry in the opposite direction--turns thoughtful. "Go figure."

Warily, Sam says, "What?"

"That's actually a pretty good idea," Dean says, more to himself than in response. He grins at Sam and saunters his way back to his bed, sitting himself down casually on the edge.

"Whatever it is you're thinking, the answer's no."

"Sammy." Dean somehow forces Sam's perfectly decent voice into a incredibly disturbing purr. "Do a guy a favour. Can't leave me hanging like that," he says, looking pointedly at the haphazard pile of blankets in Sam's lap.

Sam blinks. The rusty gears in Dean's relatively unused brain take a long time to get moving. There are synapses in his brother's head that Sam's sure haven't been used since conception.

"You're unbelievable," Sam finally says.

"C'mon. Haven't you ever wondered what you look like? It's my body, I'm giving you my full permission."

"No. God." Sam flings up his hands helplessly. "I take it back. You're not unbelievable. You're _you_."

"Technically, right now I think I'm you," Dean muses, wiggling back on a pile of pillows, getting comfy. "And if you don't do right by my body, I think we're gonna have a problem here."

"I- You- I'm not jerking you off for your own sick enjoyment!"

To Sam's complete surprise, Dean shrugs. Then he says, "Okay, you watch," and jams a hand straight down Sam's pants.

"Get my hand off my dick!" Sam bellows.

Dean's eyes go a little round. For a moment, Sam thinks it's because he's finally managed to cow Dean into submission, but no. Hitching up his hips, Dean whips down his pants and stares.

Then his lips purse in a lewd whistle.

"Dean!" Sam surges up off the bed, nearly killing himself when his legs tangle in the blankets. Which reminds him that he's _naked_, and Dean has his _cock_ is in his _hand_ but he's not the one currently in control of either.

And perhaps it might be a little awkward to touch Dean in this particular situation, so Sam thumps back down at a complete and utter loss.

Dean pays these events no mind, as he's much too busy playing with Sam's dick.

Sam is _horrified_.

"Not a bad set up you got here, Sammy," Dean says, not bothering to look up from where he's running a thumb over and over again along the flared ridge. He's fully hard, curving gently upward with just a little slick at the tip, and in the privacy of his own head, Sam could possibly admit that he's never seen himself from this angle before and it's not a bad view.

Meaning he could be about as narcissistic as Dean after all, which for a moment is immensely more distressing than the fact that the cock he's currently attached to is fairly interested in the proceedings.

Dean runs his fingers over the flat of his tongue before reaching lower to rub at his balls. Surprisingly, he doesn't say a word about the clean-shaven skin that meets his fingertips, just grunts softly and fists his other hand firmly around the shaft.

"This," Dean starts, breaking off to lick his lips and flick a glance up at Sam, "this's pretty good."

Later, Sam will decide what happens next is inevitable. His borrowed grey-matter clicks over into default setting number one, sibling rivalry, and he determinedly flings the blankets away. Cool air rushes in, giving rise to goosebumps all over his skin, and he feels a familiar rebellious smirk curve his lips before he licks his palm wet.

"C'mon," Dean goads, "go for it, Sammy."

Sam drops back against the messy bedding, hiking his knees up and spreading them wide. The jolt of pleasure when he first wraps his hand around his--Dean's, _Dean's_ awfully pretty cock--knifes deep into his gut, shocking a noise out of him.

"C'mon, c'mon." Dean spits into his palm, the sound of wet skin-on-skin suddenly so much louder.

Sam thrusts up into the tight circle of his hand, curiosity causing the other to wander higher up, blunt nails scraping lightly over one nipple. He takes it between his fingers and twists, mouth dropping open wide when it feels even better than expected.

"Yeah," Dean says, voice pitched low. "I like that. Fuck, you look good doing that to me."

Something about that nearly blinds Sam with lust. He feels the high-pitched moan creeping up his throat, realises he's hearing what _Dean_ sounds like during sex, and then he can't hear the sound of Dean jerking off over all the god damned noise he's making.

Sam twists around to bring Dean back into view, like if he can't hear it anymore he has to watch it. It's incredibly hot and surreal and awkward to see his body move when he's outside it. Equally so is the thought that he's currently _in_ his brother's, and when Dean's fingers creep lower into the thick shadows between his legs, he knows that Dean's about to find out what Sam really feels like on the inside.

"Harder," Dean grates out, gaze catching on Sam's faltering hand. "Christ, Sam, you feel fuckin' awesome." He rubs his face against the pillow, scrubbing sweat-slicked hair out of his eyes. "You gotta get laid more. Cryin' shame to keep this from the world."

What they're actually doing finally slams into Sam's like a Mack barrelling straight down I-40 at midnight. It doesn't matter that it's technically Dean's hand he's using, it's _him_, he's doing it, touching his brother's body and getting off on the thickness of Dean's cock, the way the lamplight glistens on the precome dripping steadily from the tip, the sound of his brother's pleasure-harsh voice filling up the room.

"Don't you," Dean snarls. "Sam."

With shame souring his stomach, Sam reluctantly opens his eyes. He doesn't want to meet Dean's gaze but the alternative, and exactly where Sam gets stuck, is watching the sinuous flex of Dean's hips as he fucks himself down on his own fingers.

As he fucks _Sam's_ body open, and the ugly jerk in Sam's stomach this time around is pure jealously that he can't feel it.

"Wanna see you," Dean says, the trembling in his limbs stealing its way into his voice. "Wanna see you make me come, Sam, don't make me beg."

Damning them both to hell for sure, Sam tugs his dick faster, pleasure swelling up startlingly quick to tear the breath out of his lungs. He comes harder than he ever has, feels it splatter sticky-hot on his chest, imagines it worse than the bite of a brand and just as permanent. Even when he gets his own body back, Sam's going to know.

He'd like to claim he didn't think before smearing a hand through it, lifting that hand to his face to taste his brother's come, but he did. He couldn't stop thinking about it. He _didn't_ want to stop thinking about it, and now he knows exactly what Dean's come feels like sliding across his tongue and down his throat.

Dean makes a noise meant to get his attention. Sluggishly, Sam rolls up onto his side, knowing he's doing it so Dean can see the shiny smudges left behind on his skin. He feels so filthy for it. Filthy and perfect, and it royally fucks with his head.

Dean's hand is on his cock, unmoving except for the tiniest twitches of his fingers as he rocks down. Realisation dawns slowly, because there's no way, Sam knows his body and it's not _wired that way_, but Dean fully intends to get off with just a fingerfuck.

Hoarsely, Sam asks, "Can you?"

Biting his lip, Dean nods. His shoulder's twisted so sharply it must hurt though there's no trace of it on his face. He gulps down air like a dying man, lips moving in a silent stream of words that Sam finally figures out is his fucking name, over and over.

"C'mon, Dean," Sam says, tripping only slightly over his brother's name. "Show me how I come."

The sound ripped out of Dean's throat is like nothing Sam's heard before. Worse than pain, better than pleasure, Dean arches up with it, lower back and ass lifted clear off the bed. The hand on his cock does nothing more than hold it steady so thick white streaks of come land squarely in the middle of his chest.

He sinks back down in slow motion, quaking so badly his hands are shaking when he pulls them away. He licks his lips, staring down at the slick cooling there, and sits up slowly, watching it begin to drip down.

Faced with Dean, Sam doesn't know what to do. The goosebumps prickling his skin are from the chill he can feel now in the early morning air.

Dean glances up. Uncertainty twists his mouth. "Guess we should figure out what caused the switch," he says, and if his voice wasn't so fucked, Sam could almost believe that's the end of it.

"Yeah," Sam replies. He feels shaky on the inside. Part of him wants to blame Dean for everything and that part knows Dean will let him. Accountability is something it took Sam a long time to learn. But he's just as culpable as Dean in this, he wanted it just as bad and he came just as hard.

"I want you to sleep with me," he says before he can swallow the words back down where they'll burn like acid.

Dean startles. "You want what?" He scrubs his hands up over his face into his hair. At first, Sam tries not to think about Dean breathing in the smell of his cock before he realises how much he actually _wants_ to.

"This is fucked," Dean says eventually. "Really, really fucked. I didn't mean for it to be like this, I-

"Maybe you did," Sam interrupts. "I just- I don't know what this means. And I want to."

"Sam," Dean says, and what he means is _just don't leave_.

"We'll figure it out," Sam tells him, the same thing Dean's told him countless times about everything from homework to girls to Dad. "I'm serious about you sleeping with me," he adds when Dean looks ready to retreat to the safety of the bathroom for the next five and a half months.

Dean looks at Sam warily, like he's sure Sam's going to break out the punchline any minute. He goes to the bathroom to get a damp cloth without bothering to cover up. When he comes back, he hands it over, gaze bouncing around the room as Sam cleans up before it awkwardly lands on Sam's.

"Now?" he asks.

The thought's as terrifying as it is appealing. Sam wets his suddenly dry lips. "First thing we should do is reverse the switch," he says. "There's no way I'm letting you eat three pounds of pie in my body."

It's slower than usual, but Dean's grin when it appears is just as obnoxious as ever. "Yeah, what else aren't you gonna let me do in your body?"

Sam whips the facecloth at Dean's belly. Everything's awkward and stupid and fucked up, and Dean's looking at him like maybe he's got all the answers this time around, but it doesn't feel horrible.

In fact, it feels kinda like something right.


End file.
